"You shall not uncover the nakedness of your mother's sister nor of your father's sister, for that would uncover his near of kin. They shall bear their guilt.
Leviticus 20:19
Surrounding context
20:18 If a man lies with a woman during her sickness and uncovers her nakedness, he has exposed her flow, and she has uncovered the flow of her blood. Both of them shall be cut off from their people.
20:19 "You shall not uncover the nakedness of your mother's sister nor of your father's sister, for that would uncover his near of kin. They shall bear their guilt.
20:20 If a man lies with his uncle's wife, he has uncovered his uncle's nakedness. They shall bear their sin; they shall die childless.